Saturday, July 28, 2007

The Black-masked Warbler

I drove slowly along the refuge road at Brigantine on the New Jersey coast, watching the small birds popping up from the reeds and grasses and disappearing again quickly. Most were Song Sparrows still in the early stages of their annual breeding cycle - the males singing and defending their territory - the females building nests. Between scanning the mud flats for shorebirds, I was checking out these small birds, looking for the Seaside Sparrow or the more elusive Saltmarsh Sharp-tailed Sparrow. Occasionally I saw the Seaside Sparrow clinging to the top of a broken reed and singing his weak imitation of a Red-winged Blackbird.

A small brown bird flew across the narrow road, its flight and profile different from the ever-present Song Sparrow. It grabbed onto the top of a brown grass stalk. I grabbed my binoculars, hoping for a brief glimpse of the secretive Sharp-tailed before it dropped out of sight. The brown-backed bird turned, and I saw a bright yellow breast. From the side of its head, across both eyes and brow, it wore a black mask. He quivered with attention as he surveyed his neighborhood, then sang out with “witchity-witchity-witchity.”

In the moist, young forest along the Delaware River in Pennsylvania, I heard several warblers and vireos singing and calling in the brushy understory and the canopy overhead. They were moving slowly as they foraged among the leaves. Glimpses were brief, only enough to know that a bird had gone to a new perch or new branch. Softly, I tried to call them down - “phish, phish, phish.” The strange sound will sometimes attract the birds. But this day, they were unimpressed and out of sight.

I tried again - “phish ... pish ... pish.” There was movement in the bushes. I watched and saw movement again. My binoculars focused on the small bird whose curiosity got the better of his hunger, or caution. He wore a black mask above his yellow chin and breast. He chipped loudly as he checked out the disturbance, then dropped into the thick protection of the bush. From deep in the tangle, I heard “witch-i-ty ... witch-i-ty ... witch-i-ty.”

Across the road near my home are the remnants of a pasture edge - a few tall young maples and oaks rise above the melange of cherry, honeysuckle and other small trees and bushy plants. Walking along the road, I heard a Chestnut-sided Warbler singing from a tree top. I saw him moving along a branch that had not yet fully leafed out. He paused, lifted his head and sang his “pleased-pleased-pleased-to-meetcha.”

I wanted a closer look at the Chestnut-sided, but had no binoculars with me. So I tried to “phish” him down. He moved immediately, disappearing into the foliage above, and sang again. From the thicket of roses, willows, and honeysuckle, a small bird came to inspect the neighborhood disturbance. To emphasize his territorial prerogatives, he cocked his short tail up and raised his black-masked head. “Watcha-see, watcha-see, watcha-see.”

The small black-masked bird - common in coastal marshes, common in the brushy edges of fields, common in alder swamps, common in the understory of open forests, common in open wetlands, common in the shrubbery along streams - is commonly known as the Common Yellowthroat. The Common Yellowthroat is common in numbers, but uncommon in much of its behavior. He is a warbler, a rather stubby and short-tailed warbler. He is a nonconformist - the only warbler who nests in open marsh, but also content to nest wherever he can find relatively moist and dense habitat.

Watch the behavioral antics of the black-masked Common Yellowthroat, and you might think you are watching a wren. He has the cocked-up tail, the quivering intensity, the curiosity and pugnacity that is commonly associated with the wren family - all of which is markedly uncommon in the warbler family.

The Common Yellowthroat is a very uncommon type of warbler. He doesn’t seem to know what he is supposed to be. But then neither did the early naturalists; they named him Geothlypis trichas; the elements of the name mean successively “earth,” “a kind of finch,” and “a thrush.” Those early naturalists got it wrong, but the rules of scientific nomenclature require that their mistakes be perpetuated. Only the “geo” (earth) part is partly correct; the Common Yellowthroat usually nests very close to the ground.

As ubiquitous as the Common Yellowthroat is (there is hardly a day of birding during the summer when I don’t see or hear him) he is my favorite bird. When he pops out of the thicket and complains about my intrusion on his peace, I can only smile ... and apologize for having disturbed him.

Forbush captured the appeal of the Common Yellowthroat as succinctly as any writer: “To make his acquaintance one has only to visit his favorite haunts ... when presto! up bobs that masquerading scrap of animated feathers, nervously voicing his alarm with a variety of scolding chirps and chattering notes, his black eyes sparkling with excitement. Suddenly he explodes in a vigorous outburst of song, ... and darting impatiently here and there in the low undergrowth, plainly announces that his privacy has been disturbed; but his curiosity and indignation are soon over, and scurrying to the shelter of his retreat, he leaves the cause of his disquietude flooded with emotions of surprise and delight. The Yellowthroat captivates one’s fancy.”

At dusk early this week, I heard the “tu-tu-tu ... tu-tu-tu” of a Black-billed Cuckoo. Stalking the sound, I determined that it was coming from somewhere in the mid-branches of a maple tree. I peered into the dark branches, circled around the tree, searching for bird, but the fading light of the day rendered the search futile. My bare feet chilled from the early dew on the grass, a contrast to the humid warm air of the evening.

I gave up and retreated to the porch. From somewhere along the brushy banks of the river, I heard the New England dialect of the Common Yellowthroat teasing me - “watcha-see ... watcha-see ... watcha-see.”

“Not much tonight, my friend,” I answered.

The birding is always good when the black-masked Common Yellowthroat is around.

Saturday, July 21, 2007

The Blue Jay - One of the Smart Birds

During the last week, I’ve had a couple of people tell me that they do not like Blue Jays. I responded that the reason so many people don’t like Blue Jays is because they are smarter than we are.

That Blue Jays are smarter than humans may not be strictly true - although I am not always very impressed by the intelligence exhibited among our species. What is true is that Blue Jays, as members of the Corvidae family, have the highest degree of intelligence among the birds. The Corvids, which include crows, ravens, jays, and magpies, have astonishing memories and exhibit the ability to solve problem. Naturalists have recognized for years that members of this family have languages of their own. When we listen to Blue Jays, we hear a wide variety of calls, clucks, gurgles and bubbles. The variety and complexity of these sounds - noises we sometimes call them - is more correctly described as their “language” by which they communicate issues of concern among the Blue Jay population.

The Blue Jay has a reputation as a noisy bird, a characteristic shared with its closest relative, the Steller’s Jay of the western mountains. Both belong to the Genus, Cyanocitta, which comes from the Greek meaning “chattering blue bird.” The Blue Jay is Cyanocitta cristata; the species name means “crested” in Latin.

The “jay” of the Blue Jay’s name probably derives ultimately from the attempt to imitate the sound that the “jay” birds make. As with many word derivations, there are alternatives. One alternative is that “jay” derives from the French, geai, so named for the gay (bright) plumage. Another suggests that it is a nickname, or short form, of Gaius - a common first name among the Romans, as in Gaius Julius Caesar.

In addition to its reputation for noise (a well-deserved reputation), the Blue Jay has been labeled a nest robber, a bird which consumes the eggs and nestlings of smaller song birds. John James Audubon established this reputation with his painting, showing three Blue Jays consuming eggs, and with his anecdotal observations and reports of the Blue Jay’s predations. This reputation has been sustained by many writers ever since.

But the evidence does not sustain the reputation. Arthur Bent in his life history of the Blue Jay, sites a study of the diet of the Blue Jay done in 1897. A researcher collected 292 stomachs in every month of the year from 22 states. He found that the Blue Jay’s diet “is composed of 24.3 percent animal matter and 75.7 percent vegetable matter .... The animal food is chiefly made up of insects, with a few spiders, myriapods, snails, and small vertebrates, such as fish, salamanders, tree frogs, mice and birds. Everything was carefully examined which might by any possibility indicate that birds or eggs had been eaten, but remains of birds were found in only 2, and the shells of small birds’ eggs in 3 of the 292 stomachs.”

The researcher concluded: “The most striking point in the study of the food of the blue jay is the discrepancy between the testimony of field observers concerning the bird’s nest robbing proclivities and the results of stomach examinations. The accusations of eating eggs and young birds are certainly not sustained ....”

The Blue Jays in my neighborhood are bringing their annual breeding season to a close. Few juveniles are being fed any longer by the adults, though they occasionally give some wing flutters and begging calls which are ignored. But the families stay together. When Blue Jays fly in, there are four to eight birds - two adults and the young that have survived from the original clutch of 2 to 6 eggs.

The whole process began sometime in mid-May when the adults began building their nest, a cup made of twigs, bark, rootlets, grass and perhaps paper, rags, and feathers. It looks something like a robin’s nest, and there is at least one report of Blue Jays expropriating a robin’s nest, to the chagrin of the robins. The two and a half week incubation is done almost entirely by the female; the male feeds her, and on occasion may spell her on the eggs. When the naked and helpless hatch, feeding is done by both parents. Eyes open after five days; feathers begin to form after a week.

By the time they are three weeks old, the young leave the nest, and the period of Blue Jay quiet is at an end. Young noisily call for their parents and then chase their parents. This continues for about three weeks. When the young have learned to feed themselves, Forbush writes, “the family roams through the woods, reveling in plenty that nature has provided for them; they are joined by others and it is a noisy rollicking crew.”

Blue Jays can be relatively long lived. Banding records have yielded ages up to 15 years, and there are many records of banded Blue Jays living 6-9 years.

Blue Jays migrate. I have been on Putney Mountain in the Fall and have watched as hundreds of Blue Jays flew across the opening on the crest of the ridge during early morning hours. But there is very little known about their migration. Banding records indicate the movement of Blue Jays from (for example) Massachusetts to North Carolina and New York to Virginia. But Blue Jays are also found year-round throughout their breeding range. Are the birds which we see in the winter birds which bred in our area, or birds which have migrated from some other breeding area, presumably further to the north? We don’t know.

A few years ago a friend in Marlboro tried banding winter birds with color bands so that he could identify them by sight during Spring and Summer. He saw some of the winter birds as breeding season began. Unfortunately, he was not able to continue the study, and few Blue Jays were among his banded birds. So the answer is still unknown, although the means of doing the study is there for a future researcher.

Blue Jays, like their Corvid cousins, cache food for later use. They have wonderful memories, but not perfect memories. (Alas, who does?) They often store one of their favorite foods, acorns, in soft soil. Unretrieved, the acorns sprout. Nancy Henry of the Highlands Nature Sanctuary in Ohio discovered that this caching of acorns by Blue Jays made them welcome partners in her reforestation efforts: “When it comes to industry and ingenuity in our own backyard, there is no better forester among the animals than our boisterous friend of the deciduous forest, the bluer-than-blue blue jay of Eastern North America.”

I have attempted this week to keep most “human elements” out of this column - those things which lead to such descriptions as rogue, thief, lawless, haughty, and boisterous, and which make the Blue Jay such a welcome and entertaining habitue of my feeders. Just the facts, you might say.

But I can’t resist finishing with a quote from another Blue Jay fan: “There’s more to a jay than any other creature. You may call a jay a bird. Well, so he is, in a measure, ’cause he’s got feathers on him and he don’t belong to no church perhaps, but otherwise he’s just as much a human as you and me.” So wrote Mark Twain. Good birding!

Saturday, July 07, 2007

Young Birds Bring Constant Activity to Bird Feeders

During the last week, I have found it impossible to sit on my back porch and read. Oh, I try. But there is such a riot of activity that I can’t even open the book.

Many neighborhood birds are bringing their nesting season to a conclusion, (though some may nest for a second or third time). The young are gathering at my feeders, sometimes following a parent. Or when the parents have gotten tired of feeding them, the young return to my feeders on their own. It seems that every bird amenable to bird feeders has brought their young around to enjoy my largess. The results are wild and raucous.

I’ve never had so many grackles. They’ve been breeding with such proficiency that the plain brown-black young form flocks, following iridescent adults here and there, their route of passage crossing and crisscrossing my yard with pauses in the apple tree, quick forays for ground seed, then off to the pines across the river.

The grackles are noisy, but they are nothing compared to the Blue Jays. The Blue Jays go nowhere without screaming about it. The young have been fluttering their wings in the apple tree, demanding to be fed, and their parents are accommodating ... up to a point. Once the point has been reached, the begging youngsters are disciplined and chased, and gradually get the idea that the free meals have ended. It is time to do for themselves.

Many young birds look almost identical to their parents when they leave the nest and begin traveling on their own. A clue to their young age is their cluelessness. I watched a young Blue Jay picking seeds on the ground. It was getting plenty to eat. The older jays shovel copious amounts of seed from the feeder as they seek the one seed suitable to their palate. The shoveled seeds supply the many ground feeders, including the chipmunks and squirrels. (My feelings about chipmunks whose cheek pouches bulge with my seed are ambiguous at best.)

The young jay was getting plenty to eat. But it clearly had little clue about any dangers or risks. It was still dealing with the unwelcome reality that mom and dad were no longer going to feed him and he had to feed himself.

On the cluelessness scale, the young Mourning Doves rank the highest. Sometimes the young doves have a scaliness to their plumage lacking in the adults, but that disappears after a short time. It is cluelessness that gives away their young age. Mourning Doves begin nesting very early in the Spring; they lay two eggs, and once that small brood has been raised, they do it again ... and again ... three or four broods a year. This means that there can be many naive youngsters hanging around. Doves are generally quiet and gentle birds, but the young exhibit these traits to an extreme. I can easily approach the feeder where they like to rest - sometimes as close as three or four feet before the youngsters finally, and reluctantly, take flight. They have no idea that two legged creatures are the most dangerous creatures in the world. For that matter, they have no idea that their gentle passivity makes them favorite prey for a Sharp-shinned or Cooper’s Hawk, also birds which are attracted to the convenience of backyard feeders.

Smaller birds are often more difficult to age. Young chickadees, titmice, nuthatches, finches, and many sparrows quickly lose their downiness and look like their parents within a few days of leaving the nest. But the chickadee on the branch over my head that impatiently flutters its wings, or the finch in the dogwood crouched and chittering with open beak is a young bird wanting to be fed, and in moments a harried parent will accommodate its demand ... for the moment.

Five Evening Grosbeaks on the platform feeder one morning included three juveniles. They weren’t begging, and their plumage was very similar to the adult females, but there was a hesitancy about their feeding which gave away their youthfulness.

An aside about bird feeders. My feeders were trashed in early June by a young bear. He came back a day later, nosing around the composter. My spouse, using her authoritative, disciplinary tone honed by many years in the classroom, admonished his misbehavior, clapped her hands and chased him off. He has not returned, and we have replaced our feeders. But to remove temptation, we bring them at night. The birds have readily adjusted, although it sometimes seems that the jays are especially noisy on those rare mornings when we sleep past 6:30.

For sheer entertainment, the woodpeckers have led the way this year. It’s been a banner year. I usually have two pair of Downy Woodpeckers and a pair of Hairy Woodpeckers which visit my suet feeder throughout the year. This summer (I am guessing) that number has doubled. It is hard to know for sure, but there have been so many young woodpeckers being fed by adults for so long (at least two weeks now, maybe three) that there must be a succession of families.

I become mesmerized watching a parent clamber over the suet cage, sometimes clinging upside down to the side or the bottom. The youngster also watches intently, creeping after the parent, squawking when it seems to be taking too long. Both are so intent on their tasks - feeding and being fed - that I can slowly approach, almost within touching distance, before they fly.

Then there is the adult picking out suet pieces who is approached by a young bird. Impatiently he chases off the youngster. Was the youngster someone else’s, hoping for a handout from any adult? Or was it still begging from a parent who had done enough and knew it was time for its offspring to fend for itself?

Young male Hairy and Downy Woodpeckers have a red cap (sometimes yellow on the Hairy) instead of red on the back of the head. So, it is possible to identify the juveniles after they have been weaned from their parents. I had a juvenile Hairy and a juvenile Downy hanging on opposite sides of the suet feeder, busily pecking away, while three more juveniles waited on the post and hanging basket for their turn. All flew off when Dad Downy flew in, followed by a juvenile female making her “ki, ki, ki, ki” begging calls. Then came mother Hairy with a fledgling in tow. She flew and he followed, and Dad Downy returned.

And so it continues through late afternoon and evening. There’s hardly any time to make dinner - just grab a quick leftover - because a young jay just made a last hopeful wing flutter before picking up seeds. Now the grackles are back. There’s a young catbird at the suet. Here comes the Hairy. There must be four Downies moving through the branches. Is it any wonder that I can’t read on the back porch with all this going on?

Sunday, July 01, 2007

When do goldfinches start to breed?

This photo of the American Goldfinch was taken in my back yard on June 24. The Vermont Breeding Bird Atlas criteria for "Safe Dates" to record the species as possible or probable are 6/25-8/1. This goldfinch has (to me) the appearance of a recent fledgling. Incubation is 12-14 days. Young leave nest 11-17 days. This means the parents would have begun nesting June 1 or earlier.

In general, I have found birds which winter in N.A. breeding 2-3 weeks earlier than the "safe date." Birds coming from the tropics, seems to be breeding closer to the "safe dates," although often exhibiting breeding activity a few days earlier. But I am working on impression. I have not analyzed my data. And to some degree, I have been restrained when doing the VBBA by the "safe dates." When data is entered in the VBBA data base, the program certainly imposed constraints.


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